Q2: Who and what does the future employer usually prompted when they have come in contact with my previous employment companies?
Ans: They will usually contact the Human Resource dept of your company or the director of the company (if it is a small company without HR dept) to verify your employment history as below;
- Base salary and allowances
- Employment period
- Character and work ethics
- Resignation/termination
- Any restriction on future employment set by the previous employer
- Will your previous company reemploy you in future?

Q1: Wouldn't that trigger my current superior that I am seeking out?
Ans: Yes and it is perfectly fine. This would resulting to your immediate superior to pay more attention to you, provided he/she is a good superior. If he/she does nothing about it, this would also tells you that it is high time for you to leave the company since he/she is no longer interested in your career advancement within the company.

Just remember this, if the company (in the form of salary scheme, promotion, employment benefits) or your immediate superior (work opportunity, guidance) have been treating you well, the thought of leaving the company would not have comes to you in the first place. 

Q2: Revealing on company job grade trade secret
Ans: As far as Malaysia employment industry is concern, it has been a trend as of today.

Q3: PDPA breaching?
Ans: The following question has been answered earlier. Please read again if you have overlooked the answer.

Q4: Open for exploitation where I could impersonate other HR and mention my colleague or boss is seeking out and get the salary details
Ans: In the PDPA release form, it will instructs candidate to inform their HR dept from their past employment with regards to the employment background check. They will usually get in touch with the HR from the last 2 companies only.

Forumers are to refrain from commenting if you have not read through the entire thread.